Mowers for weeds growing on flat grounds or slope faces are disclosed in Japanese Laid-open Patent Application Nos. H7-87824, H8-256560, and H9-74849, for example.
The “mower for the slope face” disclosed in Japanese Laid-open Patent Application No. H7-87824 has its object to “provide a mower having a novel structure for slope faces, capable of efficiently and safely carrying out mowing operation on the slope face which has to be done regularly every year from a viewpoint of safety control of river and maintenance of fine view”, and to attain this object, “a fitting trestle also useful as a working stand is attached to the side of a bed of a moving vehicle equipped with a suspending device of a telescopic arm type and a connecting frame is coupled with the end of the slope face side of the fitting trestle by a pivot part of the connecting frame. On the other hand, rotary mowing blocks in number corresponding to the width of the slope face are connected in series to a coupling shaft end of a hydraulic motor integrated with the connecting frame and tires are attached to the outermost side of the blocks to forma rotary. mowing main body . The rotary mowing main body is made into a suspended state by the suspending device of a telescopic arm type and lag of the tire fixed side of the block in low speed traveling of the moving vehicle is controlled to provide a mower for the slope face”. Further, the “mower” disclosed in Japanese Laid-open Patent Application No. H8-256560 has its object to “enable a mower to improve a mowing work efficiency and store a surface slope mowing apparatus in a suitable state in unused time by making an effective mowing breadth of the surface slope mowing apparatus to be readily and quickly adjustable according to a length or a state of a slope linking to a side edge of a running road face”, and to attain this object, “in a mower having a surface slope mowing apparatus mowing grasses on a slope linking to a side edge of a running road face at the side of the running machine body, the surface slope mowing apparatus is constructed to a reciprocation-type performing a nip-cutting by a relative lateral reciprocate sliding of mutual a pair of upper and lower blades and supported in freely controllable of angles to a longitudinal direction, in freely controllable of a position to a mowing width direction, and in freely swung to a longitudinal direction, then the surface slope mowing apparatus controlled by pulling up upward of the machine body is shaken backward to be able to store in a rear part side of the machine body in a fallen state”. Furthermore, the “mower machine for a slope” disclosed in Japanese Laid-open Patent Application No. H9-74849 has its object to “provide a mower machine for a slope safely and surely performable of a mowing work on a steep slant surface such as a bank with a simple operation without requiring expertness in spite of not requiring much labor”, and to attain this object, “this mower machine has an unmanned mower having a mowing device in front of a self-running machine body, controlling advancing, backing and an action of the mowing device by a remote operation and performing a mowing work in its advancing and a control truck having a remote operating device controlling advancing, backing of the unmanned mower and the action of the mowing device and a shed part of the unmanned mower. An electric winch device paying out a pulling wire connected to a rear part of the unmanned mower in advancing of the unmanned mower at a speed slower than its advancing speed and winding in backing of the unmanned mower at a speed higher than its backing speed, is provided in the shed part of the control truck”.
However, since the “mower for the slope face” disclosed in Japanese Laid-open Patent Application No. H7-87824 requires a moving vehicle equipped with a suspending device of a telescopic arm type, the size of the machine is prone to be relatively increased. In the “mower” disclosed in Japanese Laid-open Patent Application No. H8-256560, regardless of the cover body that is extendable in accordance with adjustment of a position to a mowing width direction of surface slope mowing apparatus, if the cross-section of the slope face is curved, a part of weeds remain uncut since the pair of upper and lower blades are not flexible. In the “mower machine for a slope” disclosed in Japanese Laid-open Patent Application No. H9-74849, the control truck installed on the top of slope may fall off on the slope face.
Hence, the present invention has its object to provide a self-propelled mower that has a relatively simplified structure, allows adjustment of the mowing width, can be used on curved slope faces, enables pruning high place works, and is resistant to falling down.